The people of Yemen also follow a similar procedure. They warm
the stone under bright sunlight and then place it in the camel's dung. It
is then heated. Fire has the property of making chalcedony contract but
whatever remains is of high quality. It would be spoilt if thrown into
fire again, and becomes like a charred bone. All inscriptions upon it are
made by sal ammoniac and borax. When brought close to the fire, the
inscription becomes white. Chalcedony is found upon a stone which is
brilliant like beryl and has white and black markings upon it. This stone
is called 'asirn.
After being taken off the oven, it is placed upon an iron (plate)
which is firmly fixed to the ground. It is then gently ground till the
pieces as desired separate. There are no mines of the stone except for
those in India and Yemen. The chalcedony known as Rurniya is associated with Rome as the people of Rome like it. There is no mine of the
stone in Rome. Its association with Rome is like the association of a
thing with a city where that particular article is brought and then exported to the other countries.
Nasr says that the Yemenite variety has a pale gold colour with brilliance in it and its colour and pellucidity are even. Such a variety is
known as mudhahab. It has bright edges.
There is a kind of chalcedony which is reddish yellow and is humid
and lustrous. This is the Rumi variety as the people of Rome like it.
The kind that is more reddish than yellow as 'aqiq-i-aliniar. It is hard
and costly. The cost of its gem could reach three dinars or even more.
The people of 'Iraq, however, have preference for the varieties having the
colours of dates and apricots. On the other hand, the-people of Khurasan prefer the varieties having the hues of the tamarind and the liver.
With the ghubari ruby assumed as the standard of weight (= 100) by us,
it would weigh 64-3/4. It is said that a piece of chalcedony weighing 20
rath was found.
One person told me that he had seen a big chalcedony piece among
the nobles of Yemen. It would seem, from what he has described, that
the stone must have been even bigger. The colours that are desirable in
chalcedony should be free from blemishes, should be without veins and
stripes, cloudiness, darkness, whiteness, variegation and free from contradiction in colour and pellucidity.
It is said that the best chalcedony is very red with something like
stripes on its face. Nasr says that, among the chalcedony mines in India,
there is a chalcedony with black and white colours intermingling. This
variety is called the jaza 'baqrani. Its price is less than that of the real
baqrani kind.
